Delay vehicle cache init to after map upgrades in load

Split AfterLoadVehicles into two functions.
Vehicle cache init and other functionality requiring an upgraded and
valid map is now performed later in the load process.

Re-order load update for SLV_139, it is no longer required to be
performed before the first phase of vehicle updates

src/elrail.cpp

@@ -703,7 +703,11 @@ void DrawRailCatenary(const TileInfo *ti)
 void SettingsDisableElrail(int32_t new_value)
 {
 	bool disable = (new_value != 0);
+	UpdateDisableElrailSettingState(disable, true);
+}
 
+void UpdateDisableElrailSettingState(bool disable, bool update_vehicles)
+{
 	/* pick appropriate railtype for elrail engines depending on setting */
 	const RailType new_railtype = disable ? RAILTYPE_RAIL : RAILTYPE_ELECTRIC;
 
@@ -731,12 +735,14 @@ void SettingsDisableElrail(int32_t new_value)
 	}
 
 	/* Fix the total power and acceleration for trains */
+	if (update_vehicles) {
 		for (Train *t : Train::IterateFrontOnly()) {
 			/* power and acceleration is cached only for front engines */
 			if (t->IsFrontEngine()) {
 				t->ConsistChanged(CCF_TRACK);
 			}
 		}
+	}
 
 	for (Company *c : Company::Iterate()) c->avail_railtypes = GetCompanyRailTypes(c->index);
 

src/elrail_func.h

@@ -37,5 +37,6 @@ void DrawRailCatenaryOnTunnel(const TileInfo *ti);
 void DrawRailCatenaryOnBridge(const TileInfo *ti);
 
 void SettingsDisableElrail(int32_t new_value); ///< _settings_game.disable_elrail callback
+void UpdateDisableElrailSettingState(bool disable, bool update_vehicles);
 
 #endif /* ELRAIL_FUNC_H */

src/order_base.h

@@ -890,7 +890,7 @@ static_assert(DispatchSchedule::DEPARTURE_TAG_COUNT == 1 + (DispatchSlot::SDSF_L
  */
 struct OrderList : OrderListPool::PoolItem<&_orderlist_pool> {
 private:
-	friend void AfterLoadVehicles(bool part_of_load); ///< For instantiating the shared vehicle chain
+	friend void AfterLoadVehiclesPhase1(bool part_of_load); ///< For instantiating the shared vehicle chain
 	friend SaveLoadTable GetOrderListDescription(); ///< Saving and loading of order lists.
 	friend upstream_sl::SaveLoadTable upstream_sl::GetOrderListDescription(); ///< Saving and loading of order lists.
 	friend void Ptrs_ORDL(); ///< Saving and loading of order lists.

src/saveload/afterload.cpp

@@ -985,17 +985,6 @@ bool AfterLoadGame()
 	 * filled; and that could eventually lead to desyncs. */
 	CargoPacket::AfterLoad();
 
-	/* Oilrig was moved from id 15 to 9. We have to do this conversion
-	 * here as AfterLoadVehicles can check it indirectly via the newgrf
-	 * code. */
-	if (IsSavegameVersionBefore(SLV_139)) {
-		for (Station *st : Station::Iterate()) {
-			if (st->airport.tile != INVALID_TILE && st->airport.type == 15) {
-				st->airport.type = AT_OILRIG;
-			}
-		}
-	}
-
 	if (SlXvIsFeaturePresent(XSLFI_SPRINGPP)) {
 		/*
 		 * Reject huge airports
@@ -1061,8 +1050,8 @@ bool AfterLoadGame()
 	extern void AnalyseHouseSpriteGroups();
 	AnalyseHouseSpriteGroups();
 
-	/* Update all vehicles */
+	/* Update all vehicles: Phase 1 */
-	AfterLoadVehicles(true);
+	AfterLoadVehiclesPhase1(true);
 
 	CargoPacket::PostVehiclesAfterLoad();
 
@@ -1747,11 +1736,6 @@ bool AfterLoadGame()
 				SetSecondaryRailType(t, GetRailType(t));
 			}
 		}
-
-		for (Train *v : Train::IterateFrontOnly()) {
-			if (v->IsFrontEngine() || v->IsFreeWagon()) v->ConsistChanged(CCF_TRACK);
-		}
-
 	}
 
 	/* In version 16.1 of the savegame a company can decide if trains, which get
@@ -1900,7 +1884,7 @@ bool AfterLoadGame()
 	 * preference of a user, let elrails enabled; it can be disabled manually */
 	if (IsSavegameVersionBefore(SLV_38)) _settings_game.vehicle.disable_elrails = false;
 	/* do the same as when elrails were enabled/disabled manually just now */
-	SettingsDisableElrail(_settings_game.vehicle.disable_elrails);
+	UpdateDisableElrailSettingState(_settings_game.vehicle.disable_elrails, false);
 	InitializeRailGUI();
 
 	/* From version 53, the map array was changed for house tiles to allow
@@ -2872,6 +2856,14 @@ bool AfterLoadGame()
 		}
 	}
 
+	if (IsSavegameVersionBefore(SLV_139)) {
+		for (Station *st : Station::Iterate()) {
+			if (st->airport.tile != INVALID_TILE && st->airport.type == 15) {
+				st->airport.type = AT_OILRIG;
+			}
+		}
+	}
+
 	if (IsSavegameVersionBefore(SLV_140)) {
 		for (Station *st : Station::Iterate()) {
 			if (st->airport.tile != INVALID_TILE) {
@@ -3469,6 +3461,14 @@ bool AfterLoadGame()
 		}
 	}
 
+	/* Beyond this point, tile types which can be accessed by vehicles must be in a valid state. */
+
+	/* Update all vehicles: Phase 2 */
+	AfterLoadVehiclesPhase2(true);
+
+	/* The center of train vehicles was changed, fix up spacing. */
+	if (IsSavegameVersionBefore(SLV_164)) FixupTrainLengths();
+
 	/* In version 2.2 of the savegame, we have new airports, so status of all aircraft is reset.
 	 * This has to be called after all map array updates */
 	if (IsSavegameVersionBefore(SLV_2, 2)) UpdateOldAircraft();
@@ -4580,7 +4580,8 @@ void ReloadNewGRFData()
 	AnalyseIndustryTileSpriteGroups();
 	extern void AnalyseHouseSpriteGroups();
 	AnalyseHouseSpriteGroups();
-	AfterLoadVehicles(false);
+	AfterLoadVehiclesPhase1(false);
+	AfterLoadVehiclesPhase2(false);
 	StartupEngines();
 	GroupStatistics::UpdateAfterLoad();
 	/* update station graphics */

src/saveload/vehicle_sl.cpp

@@ -28,7 +28,6 @@
 
 #include "../safeguards.h"
 
-void AfterLoadVehicles(bool part_of_load);
 bool TrainController(Train *v, Vehicle *nomove, bool reverse = true); // From train_cmd.cpp
 void ReverseTrainDirection(Train *v);
 void ReverseTrainSwapVeh(Train *v, int l, int r);

src/sl/saveload_internal.h

@@ -25,7 +25,8 @@ void MoveBuoysToWaypoints();
 void MoveWaypointsToBaseStations();
 SaveLoadTable GetBaseStationDescription();
 
-void AfterLoadVehicles(bool part_of_load);
+void AfterLoadVehiclesPhase1(bool part_of_load);
+void AfterLoadVehiclesPhase2(bool part_of_load);
 void AfterLoadVehiclesRemoveAnyFoundInvalid();
 void AfterLoadEngines();
 void FixupTrainLengths();

src/sl/vehicle_sl.cpp

@@ -262,13 +262,13 @@ extern uint8_t _age_cargo_skip_counter; // From misc_sl.cpp
 
 static std::vector<Vehicle *> _load_invalid_vehicles_to_delete;
 
-/** Called after load to update coordinates */
+/** Called after load for phase 1 of vehicle initialisation */
-void AfterLoadVehicles(bool part_of_load)
+void AfterLoadVehiclesPhase1(bool part_of_load)
 {
 	_load_invalid_vehicles_to_delete.clear();
 
 	const Vehicle *si_v = nullptr;
-	SCOPE_INFO_FMT([&si_v], "AfterLoadVehicles: %s", scope_dumper().VehicleInfo(si_v));
+	SCOPE_INFO_FMT([&si_v], "AfterLoadVehiclesPhase1: %s", scope_dumper().VehicleInfo(si_v));
 	for (Vehicle *v : Vehicle::Iterate()) {
 		si_v = v;
 		/* Reinstate the previous pointer */
@@ -420,15 +420,6 @@ void AfterLoadVehicles(bool part_of_load)
 			}
 		}
 
-		if (SlXvIsFeaturePresent(XSLFI_TEMPLATE_REPLACEMENT) && (_network_server || !_networking)) {
-			for (Train *t : Train::Iterate()) {
-				si_v = t;
-				if (t->IsVirtual() && t->First() == t) {
-					delete t;
-				}
-			}
-		}
-
 		if (IsSavegameVersionBefore(SLV_VEHICLE_ECONOMY_AGE) && SlXvIsFeatureMissing(XSLFI_VEHICLE_ECONOMY_AGE)) {
 			/* Set vehicle economy age based on calendar age. */
 			for (Vehicle *v : Vehicle::Iterate()) {
@@ -439,10 +430,16 @@ void AfterLoadVehicles(bool part_of_load)
 	si_v = nullptr;
 
 	CheckValidVehicles();
+}
 
+/** Called after load for phase 2 of vehicle initialisation */
+void AfterLoadVehiclesPhase2(bool part_of_load)
+{
+	const Vehicle *si_v = nullptr;
+	SCOPE_INFO_FMT([&si_v], "AfterLoadVehiclesPhase2: %s", scope_dumper().VehicleInfo(si_v));
 	for (Vehicle *v : Vehicle::IterateFrontOnly()) {
 		si_v = v;
-		assert(v->first != nullptr);
+		assert(v->First() != nullptr);
 
 		v->trip_occupancy = CalcPercentVehicleFilled(v, nullptr);
 
@@ -498,6 +495,16 @@ void AfterLoadVehicles(bool part_of_load)
 		}
 	}
 
+	if (part_of_load && SlXvIsFeaturePresent(XSLFI_TEMPLATE_REPLACEMENT) && (_network_server || !_networking)) {
+		for (Train *t : Train::IterateFrontOnly()) {
+			si_v = t;
+			if (t->IsVirtual()) {
+				t->unitnumber = 0;
+				delete t;
+			}
+		}
+	}
+
 	/* Stop non-front engines */
 	if (part_of_load && IsSavegameVersionBefore(SLV_112)) {
 		for (Vehicle *v : Vehicle::Iterate()) {

src/vehicle_base.h

@@ -323,7 +323,7 @@ private:
 public:
 	friend SaveLoadTable GetVehicleDescription(VehicleType vt); ///< So we can use private/protected variables in the saveload code
 	friend void FixOldVehicles();
-	friend void AfterLoadVehicles(bool part_of_load);           ///< So we can set the #previous and #first pointers while loading
+	friend void AfterLoadVehiclesPhase1(bool part_of_load);     ///< So we can set the #previous and #first pointers while loading
 	friend bool LoadOldVehicle(LoadgameState *ls, int num);     ///< So we can set the proper next pointer while loading
 
 	friend upstream_sl::SlVehicleCommon;